Final answer:
The roots, dental alveoli, and periodontal ligaments collectively form a gomphosis joint, which is a specialized immobile fibrous joint in the mouth.
Step-by-step explanation:
Collectively, the roots, the dental alveoli, and the periodontal ligaments that bind the roots to the alveolar processes form a gomphosis joint. A gomphosis is a specialized fibrous joint that anchors the root of a tooth into its bony socket within the maxillary bone or mandible bone of the skull, and is functionally classified as a synarthrosis due to its immobility. The periodontal ligaments are comprised of numerous short bands of dense connective tissue that secure the teeth in the alveolar processes.